Toa greis is not just any toa, he is a prototype. Long ago when the great beings were experimenting with the creation of the toa, toa greis was the 5th prototype out of 10. He can speak the language of the great beings, and he is mostly a machine, but he has some organic features to him.

A full view of him

A close up on his upperbody

His arm, nothing new

His legs, lower legs are new

His lower body

Another view of his legs

His back

The back of his legs

His energy scythe, I know soon to be upgraded, he is sortof just a prototype of himself